GAUGINO CONDENSATION AND THE COSMOLOGICAL IMPLICATIONS OF THE HIDDEN SECTOR

We investigate the cosmological implications of models in which the breakdown of supersymmetry proceeds via gaugino condensation in a hidden sector, only gravitationally coupled to the observable sector. Semistable particles in the hidden sector are forbidden in the range between 100 eV and a few times 10(10) GeV. These constraints derived from the restrictions on energy density and nucleosynthesis are shown to have consequences for model building. As a byproduct of these investigations we point out a particularly attractive solution of the mu-problem and the strong CP-problem with a composite hidden sector axion.